Reactivity of E4_4 (E4_4 =P4_4 , As4_4 , AsP3_3) towards Low‐Valent Al(I) and Ga(I) Compounds

The reactivity of yellow arsenic and the interpnictogen compound AsP$_3$ towards low-valent group 13 compounds was investigated. The reactions of [LAl] (1, L=[{N(C$_6$H$_3$$^i$Pr$_2$-2,6)C(Me)}$_2$CH]−) with As$_4$ and AsP$_3$ lead to [(LAl)$_2$(μ,η$^{1:1:1:1}$-E$_4$)] (E$_4$=As$_4$ (3 b), AsP$_3$ (3 c)) by insertion of two fragments [LAl] into two of the six E−E edges of the E$_4$ tetrahedra. Furthermore, the reaction of [LGa] (2) with E$_4$ afforded [LGa(η$^{1:1}$-E$_4$)] (E$_4$=As$_4$ (4 b), AsP$_3$ (4 c)). In these compounds, only one E−E bond of the E$_4$ tetrahedra was cleaved. These compounds represent the first examples of the conversion of yellow arsenic and AsP$_3$, respectively, with group 13 compounds. Furthermore, the reactivity of the gallium complexes towards unsaturated transition metal units or polypnictogen (E$_n$) ligand complexes was investigated. This leads to the heterobimetallic compounds [(LGa)(μ,η$^{2:1:1}$-P$_4$)(LNi)] (5 a), [(Cp’’’Co)(μ,η$^{4:1:1}$-E$_4$)(LGa)] (E=P (6 a), As (6 b), Cp’’’=η$^5$-C$_5$H$_2$$^t$Bu$_3$) and [(Cp’’’Ni)(η$^{3:1:1}$-E$_3$)(LGa)] (E=P (7 a), As (7 b)), which combine two different ligand systems in one complex (nacnac and Cp) as well as two different types of metals (main group and transition metals). The products were characterized by crystallographic and spectroscopic methods

The MIPAS balloon borne trace constitutent experiment

A novel cryogenic Fourier transform spectrometer (FTS) has been developed for limb emission measurements in the mid IR-region from balloon-borne platforms. The FTS is a rapid scanning interferometer using a modified Michelson arrangement which allows a spectral resolution of 0.04 cm(exp -1) to be achieved. Solid carbon-dioxide cooling of the spectrometer and liquid-helium cooling of the detectors provide adequate sensitivity. The line of sight can be stabilized in terms of azimuth and elevation. A three-mirror off-axis telescope provides good vertical resolution and straylight rejection. Calibration is performed by high elevation and internal blackbody measurements. Four balloon flights were performed, two of them during spring turn-around 1989 and 1990 over mid-latitudes (Aire sur L'Adour, France, 44 deg N) and two near the northern polar circle in winter 1992 (Esrange, Sweden, 68 deg N). Limb emission spectra were collected from 32 km to 39 km floating altitudes covering tangent heights between the lower troposphere and the floating altitude. The trace gases CO2, H2O, O3, CH4, N2O, HNO3, N2O5, ClONO2, CF2Cl2, CFCl3, CHF2Cl, CCl4, and C2H6 have been identified in the measured spectra. The 1989 data have been analyzed to retrieve profiles of O3, HNO3, CFCl3 and CF2Cl2. The flights over Kiruna have provided the first ever reported profile measurements of the key reservoir species ClONO2 and N2O5 inside the polar vortex

Reactivity of E ₄ (E ₄ =P ₄ , As ₄ , AsP ₃ ) towards Low‐Valent Al(I) and Ga(I) Compounds

The reactivity of yellow arsenic and the interpnictogen compound AsP3 towards low-valent group 13 compounds was investigated. The reactions of [LAl] (1, L=[{N(C6H3iPr2-2,6)C(Me)}2CH]−) with As4 and AsP3 lead to [(LAl)2(μ,η1:1:1:1-E4)] (E4=As4 (3 b), AsP3 (3 c)) by insertion of two fragments [LAl] into two of the six E−E edges of the E4 tetrahedra. Furthermore, the reaction of [LGa] (2) with E4 afforded [LGa(η1:1-E4)] (E4=As4 (4 b), AsP3 (4 c)). In these compounds, only one E−E bond of the E4 tetrahedra was cleaved. These compounds represent the first examples of the conversion of yellow arsenic and AsP3, respectively, with group 13 compounds. Furthermore, the reactivity of the gallium complexes towards unsaturated transition metal units or polypnictogen (En) ligand complexes was investigated. This leads to the heterobimetallic compounds [(LGa)(μ,η2:1:1-P4)(LNi)] (5 a), [(Cp’’’Co)(μ,η4:1:1-E4)(LGa)] (E=P (6 a), As (6 b), Cp’’’=η5-C5H2tBu3) and [(Cp’’’Ni)(η3:1:1-E3)(LGa)] (E=P (7 a), As (7 b)), which combine two different ligand systems in one complex (nacnac and Cp) as well as two different types of metals (main group and transition metals). The products were characterized by crystallographic and spectroscopic methods

Validation of first chemistry mode retrieval results from new limb-imaging FTS GLORIA with correlative MIPAS-STR observations

We report first chemistry mode retrieval results from the new airborne limb-imaging infrared FTS (Fourier transform spectrometer) GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) and comparisons with observations by the conventional airborne limb-scanning infrared FTS MIPAS-STR (Michelson Interferometer for Passive Atmospheric Sounding - STRatospheric aircraft). For GLORIA, the flights aboard the high-altitude research aircraft M55 Geophysica during the ESSenCe campaign (ESa Sounder Campaign 2011) were the very first in field deployment after several years of development. The simultaneous observations of GLORIA and MIPAS-STR during the flight on 16 December 2011 inside the polar vortex and under conditions of optically partially transparent polar stratospheric clouds (PSCs) provided us the first opportunity to compare the observations by two different infrared FTS generations directly. We validate the GLORIA results with MIPAS-STR based on the lower vertical resolution of MIPAS-STR and compare the vertical resolutions of the instruments derived from their averaging kernels. The retrieval results of temperature, HNO3, O3, H2O, CFC-11 and CFC-12 show reasonable agreement of GLORIA with MIPAS-STR and collocated in situ observations. For the horizontally binned hyperspectral limb images, the GLORIA sampling outnumbered the horizontal cross-track sampling of MIPAS-STR by up to 1 order of magnitude. Depending on the target parameter, typical vertical resolutions of 0.5 to 2.0 km were obtained for GLORIA and are typically a factor of 2 to 4 better compared to MIPAS-STR. While the improvement of the performance, characterization and data processing of GLORIA are the subject of ongoing work, the presented first results already demonstrate the considerable gain in sampling and vertical resolution achieved with GLORIA